Photographic silver halide emulsions containing 1-carbomylmethyl-pyrazolone couplers

ABSTRACT

PHOTOGRAPHIC SILVER HALIDE EMULSION CONTAINING A MAGENTA-FORMING 1-CARBOMYLEMETHYL-PYRAZOLONE COUPLER.

United States Patent Oflice 3,574,626 PHOTOGRAPHIC SILVER HALIDE EMULSIONS CONTAINING l-CARBOMYLMETHYL-PYRAZ- OLONE COUPLERS Friedrich-Wilhelm Kunitz, Leverkusen, Willibald Pelz,

Opladen, and Fritz Nittel, Cologne-Stammheim, Germany, assignors to Agfa-Gevaert Aktiengesellschaft, Leverlrnsen, Germany No Drawing. Filed Feb. 24, 1969, Ser. No. 801,786 Claims priority, application Germany, Mar. 5, 1968, P 16 22 922.4 Int. Cl. G03c 1/40 US. Cl. 96-100 5 Claims ABSTRACT OF THE DISCLOSURE Photographic silver halide emulsion containing a magenta-forming 1-carbomylmethyl-pyrazolone coupler.

This invention relates to a color photographic material which has at least one silver halide emulsion layer which contains a magenta-forming coupler.

The term color couplers is understood to mean compounds which will react with the oxidation products of color photographic developers, especially those of the phenylene diamine type, to form colored compounds. Such couplers must satisfy many requirements; for eX- ample they should couple as rapidly as possible with the oxidised color developer to form the dye. The resulting dye should, as far as possible, only adsorb in the required region of the spectrum whereas any side absorptions in other regions of the spectrum are undesirable. Furthermore the dyes produced should be as light-fast as possible and be stable even under extreme conditions of high temperature and atmospheric moisture such as occur in the tropics. Adequate resistance to tropical conditions is, of course, also necessary for the color couplers which are incorporated in the light-sensitive layer. The previously known magenta-forming couplers have been particularly unsatisfactory in this last respect. Also, the known magenta-forming couplers do not produce dyes on color development of the required brilliance.

It is the object of the invention to find magenta-forming couplers which not only have these required properties but also show satisfactory stability under tropical conditions and have high brilliance and good fastness to light.

It has now been found that particularly suitable magenta-forming couplers for photographic silver halide emulsion layers are l-carbomylmethyl-pyrazolone compounds of the following formula:

I NH

I Rs

in which R, is (1) alkyl preferably with up to 20 carbon atoms, (2) an aryla-mino group, preferably a phenylamino group, in which the phenyl group may be further substituted, e.g. with halogen, such as chlorine or bromine, alkyl, alkoxy, sulfo or carboxyl, or (3) an acylamino group in which the acyl groups may be derived from long chain aliphatic carboxylic acids or from benzene carboxylic acids which may carry further substituents such as halogen, alkyl, alkoxy, phenoxy, sulfo or carboxyl; the acyl groups can 3,574,626 Patented Apr. 13, 1971 2 t to, N 3 i I 00 N sonar Amara-@411 The compounds according to the invention are prepared by methods known per se. The method of preparation of coupler 2 is described in detail below. The other compounds are prepared in a similar way.

PREPARATION OF COUPLER NO. 2

(I) 2-dodecyl-acetam'lide 532.8 g. of Z-acetaminophenol and 540 of dodecyl bromide were suspended in 2 litres of absolute alcohol. A solution of 46 g. of sodium in 1 litre of absolute alcohol was added to the mixture. The mixture was boiled under reflux for 5 hours. It was then filtered while hot and mixed while stirring into 8 litres of water to which 40 ml. of concentrated hydrochloric acid had been added. It was filtered under suction and the product was washed with water and methanol. The crude product was recrystallized from methanol. The yield was 612 g. of melting point 61-63 C.

(II) Z-dodecyloxy-aniline 420 g. of 2-dodecyloxy-acetanilide were dissolved in 1,300 ml. of alcohol, and a solution of 430 g. of potassium hydroxide in 430 ml. of water was added. The mixture was boiled under reflux for hours. It was then cooled to a low temperature, suction filtered and washed with methanol. 320 g. of 2-dodecyloxy-aniline of melting point 37- 39 C. were obtained on recrystallization from methanol.

(TH) 2-dodecyloxy-chloroaeetanilide 273 g. of 2-dodecyloxy-aniline were suspended in 2.5 litres of alcohol. 40.8 g. of chloroacetyl chloride were added dropwise with stirring at -5 to 0 C. At this temperature the following reagents were added dropwise successively: ml. of an alcoholic potassium hydroxide solution (55.3 g. KOH in 480 ml. of alcohol), 40.8 g. of chloroacetyl chloride, 150 ml. of alcoholic KOH of the above concentration, 40.8 g. of chloro-acetyl chloride, 180 ml. of alcoholic KOH of the above concentration, 40.8 g. of chloro-acetyl chloride and lastly another 150 ml. of alcoholic KOH. The mixture was stirred for 10 minutes, poured into 2,5 litres of water and acidified with 5 N HCl until acid to Congo red. The reaction mixture was suction filtered and washed with a large quantity of water. The air-dried crude product Was recrystallized from alcohol. The yield was g., melting point 7274 C.

(IV) 2-dodecyloxy-hydrazinoacetanilide 175 g. of 2-dodecyloxy-chloroacetanilide were suspended in a solution of 96 g. of hydrazine hydrate in 500 m1. of alcohol. The mixture was heated up to a temperature of +70 C., at which temperature all the reactants went into solution. The solution was then stirred for 30 minutes at 70 C. The mixture was then poured while stirring into 2 litres of ice water, acidified until acid to Congo red, filtered with suction and washed with 2 N HCl and lastly with water. The hydrochloride was dissolved in 750 ml. of Warm methanol, adjusted to pH 10 with 5 N NaOH and then diluted with 2 litres of ice water. The product was filtered with suction and washed with a large amount of water. The yield of pure, colorless crystals was 117 g., melting point 44-46" C.

(V) 1- [N- (2-dodecyloxyphenyl) -carbamylmethyl] 3-amino-pyrazolone-( 5 117 g. of 2-dodecyl-hydrazinoacetanilide are suspended in 150 ml. of pyridine. 74 g. of diethyl monoiminomalonate hydrochloride were added at temperatures between 0 and +5 C. The reaction is exothermic. The reaction mixtures was stirred for 2 hours at 0-10 C. and then for 2 hours Without cooling. 220 ml. of methylate solution (85 g. of Na/litre of methanol) were then added to the solution and the solution was boiled under reflux for 30 minutes. The reaction mixture was then poured into a mixture of 300 ml. of 5 N HCl and ice and then made acid to Congo red with 5 N HCl. The waxy product was separated by suction filtration and washed with water. The crude product was stirred up with a little methanol, separated by suction filtration and washed with methanol. The crude product was purified by recrystallization from 250 ml. of alcohol with the addition of active charcoal. The yield of yellowish crystals was 50 g., the melting point 103-l05 C.

(VI) Coupler 2 50 g. of the above aminopyrazolone were suspended in.

300 m1. of ethyl acetate and heated to boiling. 23 g. of o-sulfo-benzoic acid anhydride were added near the boiling point of the solution. The whole reaction mixture first dissolved to form a clear solution but after 3 minutes, the coupler started to precipitate in crystalline form. The reaction mixture was boiled under reflux for 30 minutes. The mixture was cooled to +50 C., filtered under suction and washed with ethyl acetate until the washings were colorless. The yield was 50 g. of colorless crystals of melting point 225-226 C.

The color couplers according to the invention have excellent stability to moist heat. The dyes produced from them in the course of the color-producing development are also stable under extreme climatic conditions at elevated temperatures and in very humid conditions. In addition, they have excellent fastness to light. Their absorption properties are very good. The color couplers according to invention couple extremely rapidly with the usual developers. The dyes obtained on color development with the color couplers according to the invention have an excep tionally high brilliance.

The color couplers according to the invention may be incorporated in a difiiusion-fast form into the light-sensitive silver halide layers. This can be achieved in known manner by dissolving color couplers substituted with long chain alkyl radicals and with water-solubilising groups in the casting solution so that they are present in the emulsion layer in dissolved form. Alternatively the color couplers may be emulsified in the emulsion layer. Such proc esses have been known for a long time and can be easily applied in the present case.

To achieve this aqueous solutions of the new compounds may be mixed with the silver halid emulsions. According to another known method, the new compounds, as long as they are hydrophobic, are emulsified in gelatin, using a solvent, with or without an oil-forming agent, the emulsion is dried, again swelled in water, and mixed with the silver halide emulsion.

Processes are also known in which the color coupler is dissolved in an organic solvent and this is mixed directly with the silver halide emulsion and the solvent is then left to evaporate. The color couplers according to the invention are also suitable for use in these processes. These emulsions are then made up into one-layered of multi-layered materials on a support.

The new dye-forming substances may be added not only to the light sensitive silver halide emulsion layer itself but also to an adjacent non-sensitive layer. They may also be developed-in into the photographic material together with the color developer.

Any color-producing developers which contain a primary amino group may be used for the development. Those of the p-phenylenediamine type, e.g. N.N-diethyl-pphenylenediamine, N monomethyl p-phenylenedia-mine, N,N-dimethyl-p-phenylenediamine, 2-amino-5-diethylaminotoluene, N butyl N w-sulfobutyl-p-phenylenediamine and the like are preferred.

The known hydrophilic film forming agents such as protein, especially gelatin, polyvinyl alcohol, polyvinyl-pyrrolidine, cellulose derivatives such as carboxyalkyl-cellulose, especially carboxymethyl cellulose, derivatives of alginic acid and their alkali metal salts or esters are suitable for use as binders for the layers.

The magenta-forming couplers according to the invention are preferably added to green-sensitized photographic emulsions. Such emulsions may in the usual way contain in addition chemical sensitizers. In additon, these layers may be stabilized by known additives, especially by the azaindene dervatives described in the publicaton by Birr in Z. wiss. Photo. 47 (1952), pages 2-28.

Example-5 milli-moles of coupler 2 are dissolved in 125 ml. of an aqueous sodium hydroxide solution of approximate pH 9.

62.5 g. of a silver bromide emulsion which contains 80 g. of silver bromide and 82.5 of gelatin per kilogram are mixed with 187.5 g. of a 7.5% aqueous gelatin solution and the above color coupler. The mixture has a pH of about 6.5. 100 ml. of a 1% methanolic solution of 4- hydroxy-6-methyl-l,3,3a,7-tetraazainden, 120 ml. of a 5% aqueous saponin solution and 60 ml. of a 0.5% aqueous solution of chromoacetate are added. The mixture is then made up to 900 ml. with water. The casting solution is cast on a cellulose acetate support and dried.

The film is developed in a conventional sensitometer behind a grey step wedge, using a conventional color-forming developer which contains N-ethyl-N-w-sulfobutyl-pphenylene diamine as developer. It is treated with a bleaching bath and fixed in known manner. A magenta step wedge with brilliant colors is obtained.

We claim:

1. A light-sensitive photographic silver halide emulsion layer which contains a magenta-forming color coupler of the following formula:

in which:

R is alkyl having up to 20 carbon atoms, an arylamino group or an acylamino group;

R is hydrogen or alkyl having up to 18 carbon atoms;

R is hydrogen, alkyl having up to 20 carbon atoms, an

aryl group or a heterocyclic group.

2. An emulsion according to claim 1, wherein R represents hydrogen.

3. An emulsion according to claim 1, wherein R represents an acylamino group in which the acyl group is derived from an aliphatic carboxylic acid which bears a sulfo group or is derived from a benzoic acid which bears a sulfo group.

4. An emulsion according to claim 1, which contains a coupler of the following formula:

CO l

5. An emulsion according to claim 1, which contains a coupler of the following formula:

References Cited UNITED STATES PATENTS 2,369,489 2/1945 Porter et al 96-100 3,330,660 7/ 1967 Van Poucke et al 96-100 J. TRAVIS BROWN, Primary Examiner 

